REDWOOD CITY – Martin Hernandez fixates on his teammate 100 feet away, the one holding the end of a hose gushing wet concrete inside a giant hole slated to become an underground parking garage in downtown Redwood City.

Mark Kaufman - Scienceline, New York University

Asphalt — thick, black and pungent — has held our roads together more than 100 years.

It forms naturally, is cheap and easy to repair, but come summer, it swelters.